Winter Storage Covers
Made a ridge pole out of 4" PVC that runs the length of my 30 foot boat, about 3 feet above cabin top. Legs and bases made of PVC fittings. 20x40 white poly tarp is spread out evenly. Got it online and still serviceable after 6 years, getting to end of its life though. Along the long edge of tarp I built a bunch of blocks out of plywood with large hole drilled through. Screwed these to a backing block of wood evenly along edge. Then just crisscross under the boat, the blocks let me pull the tarp pretty tight. These are a lot stronger than grommets and have never pulled out even pulling tight.
Has made it through many Maine winter storms and is steep enough it nearly sheds all snow on its own. Also rigged in such a way there are very large openings fore and aft for ventilation and access. Mast is stored on deck in a custom cradle nearly entirely inside cover. Cheap and has worked very well. I have found the ridge pole does not need to be tied down or supported, a tightly pulled cover holds it in place.
You will regret the things you did not do, more than the things you did.
Get out there!
Saco Bay, Maine
2001 Beneteau Oceanis 361